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Finding the Fourth Proportional to 80.32, 120.90 and 71.50

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Solution

The fourth proportional to 80.32, 120.90 and 71.50 is: 107.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.32 : 120.90 = 71.50 : x
  2. Step 2: Convert to fraction form
    80.32/120.90 = 71.50/x
  3. Step 3: Cross multiply
    80.32x = 120.90 × 71.50
  4. Step 4: Simplify right side
    80.32x = 8,643.99
  5. Step 5: Solve for x
    x = 8,643.99/80.32
  6. Step 6: Final answer
    x = 107.62

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.